Data retention settings can be made in the software client or WholesaleBackup Windows server as described here.
The meaning of these settings is as follows.
At the end of a backup, a file retention rollup process takes place where the client determines what old versions of files it may delete from its own local backup folder as well as the remote backup server.
First, the backup client identifies all files that are older than the retention. It then checks to see if there is a newer version of the same file that is at or older than the retention period. If so, the older of the file will be aged out. If you set the retention to zero, then this check is skipped, and no file will be aged out based on when it was backed up.
After this identifies all files to age out based on when they were backed up, it checks the total number of versions of the same file that have been backed up. If there are more versions than the versions setting, the older versions are aged out. If the versions is set to zero, then this check is skipped, and all versions newer than the retention will be kept.